For a variety of reasons, it can be desirable to treat either mined or created materials. This treatment can include alteration to create another form of the material or components of the material that allows for specific processing and/or alternative separation techniques to be utilized, for example. Components of materials that can make alternative treatment, specific processing, and/or separation techniques desirable include but are not limited to toxic, regulated, and/or valuable materials such as uranium materials, actinide materials, and/or fission materials.
As an example, uranium materials can be treated to provide a uranium fluoride material which can be used in the uranium fuel cycle. Uranium fluorination is performed in the existing nuclear fuel cycle to fluorinate uranium recovered both from ore and/or from spent nuclear fuel. These fluorination processes rely on many hazardous, highly reactive, and highly toxic fluorinating agents. As an example of a currently used process, in a reprocessing plant, uranium is recovered as uranyl nitrate hexahydrate (UNH), calcined to uranium trioxide (UO3), reduced to uranium dioxide (UO2) using hydrogen derived from cracked ammonia, converted to UF4 by HF (NFPA rating Health=3; Reactivity=2) at 300 to 500° C., and finally converted to UF6 by F2 (NFPA rating Health=4; Reactivity=4) at 500° C. The process for converting natural uranium to UF6 is similar.
Fluorinating agents used or proposed for use in the fluoride volatility-based reprocessing approach include hydrogen fluoride (HF) and/or diatomic fluorine (F2), difluorodioxide (FOOF), chlorine trifluoride (CIF3), and bromine trifluoride (BrF3). These fluorinating agents are considered highly toxic, highly reactive, and hazardous and some can produce hazardous by-products. In particular, CIF3 fluorination by-products are explosive or can react explosively with water or organics. These highly toxic reagents necessitate the use of substantial safety and environmental controls. These controls can add substantial cost to the processing of uranium materials.